Field of the Invention:
The invention relates to a feeding unit and to a method for feeding an element to a treatment unit of a machine tool.
In the automated treatment of an element, for example a component or a joining element, in particular with the aid of a robot, an automated and individual feeding of the individual elements to the treatment unit is required. The joining elements are in this case, for example, screws, nuts, fastening bolts, and also rivets, in particular blind rivets and blind rivet nuts.
A treatment unit is therefore understood here, generally, to mean a unit by which a component or joining element is introduced or attached in or on a workpiece at an intended position. The treatment unit is in this case, in particular, a setting unit by which a rivet is inserted into the workpiece. The treatment unit may also be a screwing unit for screwing a screw element into the workpiece or a punching unit for shooting a bolt into a workpiece. The machine tool having the treatment unit is therefore, in particular, a plug-in, press-in, punching, screwing, riveting or blind-riveting tool.
To attach the element to the workpiece, an advancing movement of the treatment unit with respect to the workpiece is normally required. So as not to disturb the treatment operation, therefore, the feeding unit should lie outside the treatment plane spanned by the workpiece. For good access even to confined installation spaces, for example in a motor vehicle, the feeding unit should have as small a build as possible, so as not to impede the freedom of movement of, for example, a robot hand, having the treatment unit, of an industrial robot. Furthermore, the feeding unit must ensure a rapid feed of the element to the treatment unit, in order to achieve as short cycle times as possible.
In the connection of two components by blind rivets, for example, a riveting unit is used, in which the blind rivet to be set is first fed manually from the front to a mouthpiece of the riveting unit. Subsequently, the riveting unit, with the blind rivet in front, is introduced into a through bore (rivet hole) of the components to be connected, and the blind rivet is set. A blind rivet residual plug torn off during the setting operation is usually collected in a collecting container of the riveting unit which is disposed in the axial direction at the rear end of the riveting unit.
Blind rivet technology is increasingly employed, particularly also in the motor vehicle sector, for the connection of components which have hitherto been connected to one another, for example, by welding. Motor vehicle manufacturing is automated to a high degree, and the connection of the body components is for the most part carried out with the aid of welding robots which automatically approach the welding points and weld the components to one another automatically.
For the automated operation of setting a blind rivet with the aid of an industrial robot, an automated feed of the blind rivets to the riveting unit is required. In order to allow as short cycle rates as possible, a rapid feed is in this case necessary.